Tomorrow, it can be said with some certainty, Paul Kagame will be re-elected president of Rwanda. Mr Kagame's is not the only name on the ballot, but he is the favourite by far. His rivals have scarcely featured in the campaign, which has at times resembled more a lap of honour by the incumbent.

That might well have been the case even if the election were conducted freely. But opposition groups have been excluded, journalists have been intimidated and dissenting voices have been silenced, sometimes violently.

Mr Kagame is widely credited with bringing security to a country that was torn apart by genocide in 1994. His regime has acted as a guarantor of stability sufficient to attract foreign investment and international aid. The economy has doubled in size in the last five years and is expected to grow by around 6% this year. In comparative surveys of corruption and transparency, Rwanda's government does better than the rest of east Africa.

In that respect, Rwanda is sometimes held up as an example and Mr Kagame has become something of a favoured leader for western aid donors. Britain gives some £55m in aid every year. It is generally preferable to be governed by an internationally admired leader than a reviled one. But the west's record in picking favourites gives cause for concern with regard to Rwanda.

Mr Kagame dresses as a civilian and is an elected president, but he is a soldier at heart. There is no evidence linking him to attacks on opposition leaders and army rivals. But the election campaign has been conducted in an atmosphere of intimidation familiar to all quasi-military regimes and of a kind that quickly acquires its own violent momentum.

Meanwhile, divisions between the majority Hutu population and the minority Tutsis – victims of the genocide and, under Mr Kagame, predominantly the ruling class – have not gone away. But they have been subdued by presidential fiat. Political activity that mobilises ethnic identity is barred as "divisionism".

That, perhaps, is how things must be handled to promote integration. But there have been worrying indications that Mr Kagame is prepared to use the charge of stoking division as a pretext to suppress political dissent more generally. Inevitably, given the country's bloody history, it is hard to distinguish between political grievance that is separate from the legacy of the genocide and Hutu agitation that would deny or seek to excuse the inexcusable. Western governments, meanwhile, mindful of their nations' abject failure to intervene in 1994, are timid about criticising Mr Kagame.

But the laudable goal of creating "One Rwanda" should not give the president immunity from censure. The west has a terrible record in Africa of giving individual leaders the credit for bringing stability to their countries and then accepting that, in the interests of continued stability, the leader's tenure is more important than democracy.

The time is long overdue when aid and trade policy are focused on upholding and strengthening institutions and civil society, not individuals with guns close at hand. Rwanda offers an opportunity to put such an approach to the test.

Those countries that lavish aid on Mr Kagame's regime should remind him that his greatest achievement will be one day standing peacefully aside.